Bottle Attributes - Colors

The color of glass is determined by impurities or coloring agents
present when the glass is made. Iron is the most common agent as it
naturally occurs in much of the sand used to manufacture bottles. The
amount of iron will produce varying shades of green. Very little iron
will produce a light aqua shade and a lot of iron will produce an
almost black color in the glass. Other additives will produce different
colors. For example, tin produces a white or milk glass. Some additives
act as decolorizing agent. These additives produce a clear glass,
however, this glass is often not as strong as some of the colored
glasses.

The color of a bottle has something to say about a bottle's age. Colors
used on certain types of bottles have periods of use that are not
reflective of the colors used in general. For example, there are many
clear pontiled bottles but try and find a true clear pontiled soda
bottle.

Some colors, such as canary yellow, are not known in soda and beer
bottles. Many colors were considered too costly to be used in the
manufacture of utilitarian bottles.

The colors of glass used for bottles also has a lot
riding on tradition and regional preferences. For example, the
following table shows how many different deep blue soda and beer
bottles were produced for Philadelphia and Lehigh Valley bottlers in
five year increments:

Period

Philadelphia

Lehigh Valley

1845-1849

45 bottles

1 bottle

1850-1854

21 bottles

2 bottles

1855-1859

5 bottles

5 bottles

1860-1864

1 bottle

4 bottles

1865-1869

0 bottles

3 bottles

1870-1874

1 bottle

5 bottles

1875-1879

0 bottles

2 bottles

As you can see this blue color was basically phased out in
Philadelphia by 1859 and at the same time was just becoming popular in
the Lehigh Valley. These two areas are a scant sixty miles apart and
were well connected by railroads and canals. The bottles were even
manufactured by the same glass works. Tradition and regional
preferences dictated how various bottles were colored.